Advanced nanoscale science and engineering have driven the fabrication of two-dimensional and three-dimensional structures with nanometer precision for various applications including electronics, photonics and biological engineering. Traditional patterning methods such as photolithography and electron beam lithography that have emerged from the microelectronics industry are well suited to fabricate two-dimensional features on ultraflat silicon and glass surfaces. However, building three-dimensional device structures involves repeated photoresist patterning and pattern transfer processes.